Cooling towers are used to cool liquid by contact with air. The liquid is allowed to flow downwardly through the tower, and a countercurrent flow of air is drawn through the falling liquid by various means. A common application of liquid cooling towers is to cool water used in electrical generating systems, process plants and industrial and institutional air conditioning systems, to dissipate waste heat.
Current multi-cell, induced draft, cross flow cooling towers are constructed modularly, with hydraulically isolated hot-water basins (also referred to as “cooling cells”) that contain the water to be cooled. The water is cooled in the cooling tower internal cooling structures as it falls to a common cold-water basin beneath the tower. In order to operate efficiently, even distribution of the water between cooling cells is required in order to prevent any one cell from becoming overloaded. If excess water is directed to one cell of the cooling tower, it will not be possible to cool the flow as efficiently. As a result, both the off-tower temperature and the approach-temperature will be higher than the design values for a given tower.
Cooling cells can reach imbalance in a variety of different ways, including blockages in the spray nozzles that drain the hot-water basin. The current practice to correct imbalance in a cooling tower is to control the flow of water through the cooling water lines until basin depth is uniform across the cooling cells. Because this process is tedious, it is not always conducted. Thus, in many cases, cooling cell imbalances are tolerated and efficiency is sacrificed.
Therefore, what is needed is a cost-effective solution to solve the problem of cell-to-cell imbalance that would maintain and improve cooling tower efficiency.